3 days oatmeal detox how to make your belly flat

Recently, I needed flat belly for a special even and since it is my problem area ( whenever I gain weigh all fat seems to always go to my belly) I tried 3 days oatmeal detox. I read that Its good for you, cleans out your intestines ,makes you feel light and makes your tummy flat! Let me tell you it really works, but only if temporary (for me it was 2 days). I also heard that professional runners do that.
Basically you eat oatmeal 5 times a day for 3 days. I mixed mine with some granola musli to give more taste to it. Last meal I ate at 6pm.
It was not hard for me at all, but I love oatmeal.
Since it is a detox - you can do it only 2 times a year.
I recommend to consult your doctor before doing any types of detox or extreme diet.
What do you thing about detox? Have you ever been on one?